The present invention generally relates to a manufacture control system and, more particularly, to a distributed control system and method for controlling the production of small items of manufacture, such as batteries.
Items of manufacture, and, in particular, small items of manufacture requiring multiple processes during their production and which are produced in large quantities, such as dry cell batteries, are completed by passing the articles through a series of individual apparatuses which are specifically designed to perform one or two processes. These processing machines are often stand-alone units which operate on a bulk input/bulk output basis. This type of system is labor intensive, and lacks the capability for adequate quality control, rapid maintenance, or tracking of the manufactured articles.
Current processing equipment which typically operates in an indexed manner has a single main drive motor which drives the indexer as well as driving the application heads performing the specific process. These various operations conducted by the machines are mechanically timed and are controlled by mechanical cams. Such mechanical timing is time-consuming to setup, is not flexible, and may lack precision. Any malfunction of these machines generally requires the entire machine to be pulled off-line for time-consuming repair, thus resulting in undesirable production efficiency.
The bulk-in/bulk-out manner in which these machines operate is such that the battery cans are extracted in random fashion from a bin thereby requiring proper orientation to begin the processing and are then output from the machine into another bin after processing. The processed cans are then transported in bulk to another processing station whereupon the bin extraction and article orientation functions are again repeated thus duplicating unnecessary handling and time consuming operations. Others of these machines operate on a theory of back pressure wherein the battery cans are stacked and urged to a processing station by applying a force to the backed up cans to force the articles through the processing machine. There must always be a supply of battery cans on the input side to maintain sufficient pressure to keep the xe2x80x98pump primedxe2x80x99 thereby facilitating processing throughput. Such methods of input and output preclude the tracking of individual battery cans during processing and between discrete machines. The manufacturer therefore loses information about individual cans between product assembly or processing steps. A consequence of the random input and output is a loss of quality control on individual articles with the result being that there is little to no process data available on the articles, and what data is available is not in alignment with quality control samples taken from the processing line.
At the conclusion of the quality control sampling, the machine is again stopped and again unloaded by hand. This time-consuming but necessary function often results in a significant loss of valuable production time in addition to the excessive labor costs associated therewith. Additionally, repeated starting and stopping of the machine induces variation in the production process which can adversely affect production quality.
The current mechanically controlled machines often include one or more cams to transfer desired time sequenced motion to the processing apparatuses mounted to the machine for a desired synchronized operation. In addition to the single drive motor driving the processing apparatus, the motor also operates and drives a large mass circular dial which transports the battery cans therearound to the individual process stations on the machine. Typically, these large mass dials require a significant percentage of the power consumed by the machine to accelerate and decelerate the dial during the indexing operations. Power thus expended contributes little xe2x80x98value addedxe2x80x99 to the finished product. Also, the acceleration and deceleration of large mass dials requires a significant portion of the total time of operation which therefore severely limits the throughput of the processing machines.
The aforementioned current processing equipment employs separately controlled process stations in which battery cans were randomly dumped from one machine to another, thereby eliminating any ability to track a given battery can. Additionally, in order to conduct experimental process operations, conventional manufacturing systems commonly require that the normal system operation first be shutdown, the experimental equipment then be installed, and the experimental process thereafter conducted. Once the experimental operation is finished, the conventional system is reconfigured for normal article manufacturing. Thus, experimental processing required extensive shutdown time and labor to reconfigure the system and conduct the experimental process.
Therefore, there is a desire and need in industry and particularly in dry cell battery processing for a processing system which can operate at increased throughput and which eliminates unnecessary handling and duplicative operations to be performed on the manufactured articles. The needed processing system has the additional characteristics of being flexible, permitting off-line set-up and calibration, the ability to be quickly deployed, and capable of rapidly incorporating product design changes. Such a system is also desired to more efficiently monitor quality control on processes, including the capability of tracking a single item of manufacture through the processing system, and also the ability to test new processes and processing equipment for a comparative analysis of articles of manufacture processed normally with articles of manufacture processed with one or more test processes.
Also, it is desirable to provide for a processing system that allows for battery cans to be tracked and accounted for throughout the entire processing operation. Further, it is desirable to provide for such a processing system that allows for easy experimental processing that does not require excessive system shutdown and labor.
Further, reduced manufacturing cost and increased processing operation efficiencies are desirable to produce a cost-effective product. The added costs associated with conventional production line setup, downtime and maintenance has created the need for creative control strategies that may reduce cost to provide a more cost effective product. Automated manufacturing control systems typically employ software that is dependent on a particular computer operating system and is designed to operate a predefined production line configuration. It is desirable to provide a distributed control system that is not dependent on a particular computer operating system software, provides flexible processing capability, and is able to control multiple production line configurations with minimal reconfiguration. It is also desirable to provide a distributed control system that may continue to control production of material in the event that a process control device, such as a processor fails to perform as configured, so as to reduce processing downtime and incur less added cost. Further, there is a need for control software that is flexible to allow for use with various control systems for controlling different types of production machinery, thereby eliminating the need for dependence on the supplier of a particular hardware or software configuration.
According to one aspect of the present invention, a control system is provided that is adapted to control process operations for processing individual articles. The control system includes a coordinator controller adapted to control process operations associated with a processing system by communicating work request messages to at least one process module. The system also includes a software coordinator agent executable by the controller and configured to control the processing operation. A software process module agent is included and configured to represent a component of the process module and is executable to perform a process operation. The control system further includes a protocol adapted to allow the software coordinator agent to communicate messages with the software process module agent. Preferably, the control system employs software models such as an input/output model, a communication model, and a data distribution system model.
Another aspect of the present invention is a control system for controlling the processing operations. The control system includes a plurality of controllers adapted to control operations associated with a processing system. Each of the plurality of controllers are configured to communicate with at least another one of the plurality of controllers. A plurality of software agents, each representing a component within the control system, are provided in one or more of the plurality of controllers. The software agents are executable within any one or more of the plurality of controllers. Models for encapsulating structural architecture are preferably included in one or more of the plurality of controllers. The control system further has a protocol adapted to allow each of said software agents to communicate messages with other software agents.
A further object of the present invention is a distributed control system for controlling the manufacturing of one or more articles. The distributed control system includes a coordinating controller and a coordinator agent for monitoring processing of each article of manufacture and for coordinating the processing of each article of manufacture. The coordinating controller is networked with one or more process station controllers and is adapted to communicate with a process station agent. Each process station agent is generally adapted to initiate processing of articles of manufacture associated with a branch processing station. In addition, a process module agent is provided for each process module associated with the processing station for performing a designated process on articles. The process module agent controls the processing operation of the associated process module, while the coordinator agent preferably controls the processing operation of each article of manufacture, initiates control operations, tracks each product through the process operations, and collects information on the processing of each article. The control coordinator, process station controllers and process module agents communicate messages via a protocol.
Yet, another aspect of the present invention is a method of controlling the processing of articles. The method includes the steps of providing a plurality of controllers adapted to control a processing operations and including a coordinator agent and a process agent. Work request messages are transmitted from the coordinator agent to each of the other of the process agents including information on a process operation and designated article. The process agents perform an intended process operation, generate a work report message when the designated operation is complete, and store the work report message in memory.